Method and means for using low-compression fuels



Patented Mar. 2, 1926.

UNITED STATES PATENT OFFICE.

THOMAS MIDGLEY, .13., OF DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO GENERAL MOTORS CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

No Drawing. Application filed September To all whom it may concern:

Be it known that I, THOMAS MIDGLEY, Jr., a citizen of the United States of America, residing at Dayton, county of Montgomery, and State of Ohio, have invented certain new and useful Improvements in Methods and Means for U sing Low-Compression Fuels, of which the following is a full, clear, and exact description.

This invention relates to the art of suppressing a fuel knock when a combustible gaseous mixture containing a low compression fuel such, for example, as kerosene and gasoline is burned under a relatively high pressure. The principal objects of this invention are to employ cadmium compounds to suppress the fuel knock.

Kerosene has a critical compression pressure of about pounds. The critical com-. pression pressure of gasoline varies from about pounds for the commoner forms now marketed to about 125 pounds for aviation gasoline employed in airplane engines. These fuels are termed low compression fuels. When the vapors of any one of them is mixed with air, compressed to a compression pressure in excess of the normal critical compression pressure of the fuel, and burned, as in an internal-combustion engine, a fuel knock is produced.

I have-found that vapors of cadmium compound added to the fuel-air mixture suppress this fuel knock and permit an increase in the engine compression pressure with a normal burning characteristic of the fuel.

By way of an example of one method of carrying out my invention, I dissolve 200 grams of dimethyl cadmium Ca(CI-I in 1 gallon of gasoline having a critical compression pressure of about 75 pounds. This solution or high compression fuel is fed through a carburetor into the cylinder of an internalcombustion engine having a compression pressure of about 100 pounds, the solution METHOD AND MEANS FOR USING LOW-COMPRESSION FUELS.

18, 1923. Serial No. 663,499.

being vaporized and mixed with air as isare other alkyl compounds including diethyl' cadmium.

I prefer to employ the cadmium compounds whieh are soluble in the fuel to promote the mixing of the two. Blending agents may be employed if the cadmium compound does not dissolve readily in the fuel. The compound may be added to the fuel-air mixture just before the latter is burned.

I claim: A

1. A composition of matter comprising a low compression fuel; and a volatile cadmium compound .incorporated therein and adapted to increase the critical compression pressure of the fuel.

2. A composition of matter comprising a low compression fuel, such as kerosene or gasoline; and a volatile alkyl compound of cadmium incorporated homogeneously therein and adapted to increase the critical com pression pressure of the fuel.

3. A, composition of matter comprising a low compression fuel; and a volatile methyl compound of cadmium incorporated therein.

4. A composition of matter comprising gasoline; and dimethyl cadmium.

In testimony whereof I hereto ailix my signature.

THOMAS MIDGLEY, J n. i 

